1 /*
2  * Copyright (c) 2020 Omar Polo <op@omarpolo.com>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #ifndef GMID_H
18 #define GMID_H
19 
20 #include "config.h"
21 
22 #include <sys/socket.h>
23 #include <sys/types.h>
24 
25 #include <arpa/inet.h>
26 #include <netinet/in.h>
27 
28 #include <dirent.h>
29 #include <signal.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <time.h>
33 #include <tls.h>
34 #include <unistd.h>
35 
36 #include <openssl/x509.h>
37 
38 #define GEMINI_URL_LEN (1024+3)	/* URL max len + \r\n + \0 */
39 
40 #define SUCCESS		20
41 #define TEMP_REDIRECT	30
42 #define TEMP_FAILURE	40
43 #define CGI_ERROR	42
44 #define NOT_FOUND	51
45 #define PROXY_REFUSED	53
46 #define BAD_REQUEST	59
47 #define CLIENT_CERT_REQ	60
48 #define CERT_NOT_AUTH	61
49 
50 #define MAX_USERS	64
51 
52 #define HOSTSLEN	64
53 #define LOCLEN		32
54 
55 /* maximum hostname and label length, +1 for the NUL-terminator */
56 #define DOMAIN_NAME_LEN	(253+1)
57 #define LABEL_LEN	(63+1)
58 
59 #define PROC_MAX	16
60 
61 struct location {
62 	const char	*match;
63 	const char	*lang;
64 	const char	*default_mime;
65 	const char	*index;
66 	int		 auto_index; /* 0 auto, -1 off, 1 on */
67 	int		 block_code;
68 	const char	*block_fmt;
69 	int		 strip;
70 	X509_STORE	*reqca;
71 	int		 disable_log;
72 };
73 
74 struct vhost {
75 	const char	*domain;
76 	const char	*cert;
77 	const char	*key;
78 	const char	*dir;
79 	const char	*cgi;
80 	const char	*entrypoint;
81 	int		 dirfd;
82 
83 	/* the first location rule is always '*' and holds the default
84 	 * settings for the vhost, from locations[1] onwards there are
85 	 * the "real" location rules specified in the configuration. */
86 	struct location	 locations[LOCLEN];
87 };
88 
89 extern struct vhost hosts[HOSTSLEN];
90 
91 struct etm {			/* extension to mime */
92 	const char	*mime;
93 	const char	*ext;
94 };
95 
96 struct mime {
97 	struct etm	*t;
98 	size_t		len;
99 	size_t		cap;
100 };
101 
102 struct conf {
103 	/* from command line */
104 	int		 foreground;
105 	int		 verbose;
106 
107 	/* in the config */
108 	int		 port;
109 	int		 ipv6;
110 	uint32_t	 protos;
111 	struct mime	 mime;
112 	char		*chroot;
113 	char		*user;
114 	int		 prefork;
115 };
116 
117 extern const char *config_path;
118 extern struct conf conf;
119 extern int exfd, logfd;
120 
121 extern struct imsgbuf logpibuf, logcibuf;
122 
123 extern volatile sig_atomic_t hupped;
124 
125 extern int servpipes[PROC_MAX];
126 
127 struct iri {
128 	char		*schema;
129 	char		*host;
130 	char		*port;
131 	uint16_t	 port_no;
132 	char		*path;
133 	char		*query;
134 	char		*fragment;
135 };
136 
137 struct parser {
138 	char		*iri;
139 	struct iri	*parsed;
140 	const char	*err;
141 };
142 
143 struct client;
144 
145 typedef void (*statefn)(int, short, void*);
146 
147 /*
148  * DFA: handle_handshake is the initial state, close_conn the final.
149  * Sometimes we have an enter_* function to handle the state switch.
150  *
151  * handle_handshake -> handle_open_conn
152  * handle_handshake -> close_conn		// on err
153  *
154  * handle_open_conn -> handle_cgi_reply		// via open_file/dir/...
155  * handle_open_conn -> handle_dirlist		// ...same
156  * handle_open_conn -> send_file		// ...same
157  * handle_open_conn -> start_reply		// on error
158  *
159  * handle_cgi_reply -> handle_cgi	// after logging the CGI reply
160  * handle_cgi_reply -> start_reply	// on error
161  *
162  * handle_cgi -> close_conn
163  *
164  * handle_dirlist -> send_directory_listing
165  * handle_dirlist -> close_conn			// on error
166  *
167  * send_directory_listing -> close_conn
168  *
169  * send_file -> close_conn
170  */
171 struct client {
172 	struct tls	*ctx;
173 	char		 req[GEMINI_URL_LEN];
174 	struct iri	 iri;
175 	char		 domain[DOMAIN_NAME_LEN];
176 	statefn		 next;
177 	int		 code;
178 	const char	*meta;
179 	int		 fd, pfd;
180 	DIR		*dir;
181 	char		 sbuf[1024];
182 	ssize_t		 len, off;
183 	struct sockaddr_storage	 addr;
184 	struct vhost	*host;	/* host she's talking to */
185 };
186 
187 enum {
188 	FILE_EXISTS,
189 	FILE_EXECUTABLE,
190 	FILE_DIRECTORY,
191 	FILE_MISSING,
192 };
193 
194 /* gmid.c */
195 void		 sig_handler(int);
196 void		 mkdirs(const char*);
197 char		*data_dir(void);
198 void		 load_local_cert(const char*, const char*);
199 void		 load_vhosts(void);
200 int		 make_socket(int, int);
201 void		 setup_tls(void);
202 void		 init_config(void);
203 void		 free_config(void);
204 void		 drop_priv(void);
205 
206 /* provided by lex/yacc */
207 extern FILE *yyin;
208 extern int yylineno;
209 extern int yyparse(void);
210 extern int yylex(void);
211 
212 void		 yyerror(const char*, ...);
213 int		 parse_portno(const char*);
214 void		 parse_conf(const char*);
215 
216 /* log.c */
217 void		 fatal(const char*, ...)
218 	__attribute__((format (printf, 1, 2)))
219 	__attribute__((__noreturn__));
220 
221 #define LOG_ATTR_FMT __attribute__((format (printf, 2, 3)))
222 void		 log_err(struct client*, const char*, ...)	LOG_ATTR_FMT;
223 void		 log_warn(struct client*, const char*, ...)	LOG_ATTR_FMT;
224 void		 log_notice(struct client*, const char*, ...)	LOG_ATTR_FMT;
225 void		 log_info(struct client*, const char*, ...)	LOG_ATTR_FMT;
226 void		 log_debug(struct client*, const char*, ...)	LOG_ATTR_FMT;
227 void		 log_request(struct client*, char*, size_t);
228 int		 logger_main(int, struct imsgbuf*);
229 
230 /* mime.c */
231 void		 init_mime(struct mime*);
232 void		 add_mime(struct mime*, const char*, const char*);
233 void		 load_default_mime(struct mime*);
234 const char	*mime(struct vhost*, const char*);
235 
236 /* server.c */
237 const char	*vhost_lang(struct vhost*, const char*);
238 const char	*vhost_default_mime(struct vhost*, const char*);
239 const char	*vhost_index(struct vhost*, const char*);
240 int		 vhost_auto_index(struct vhost*, const char*);
241 int		 vhost_block_return(struct vhost*, const char*, int*, const char**);
242 int		 vhost_strip(struct vhost*, const char*);
243 X509_STORE	*vhost_require_ca(struct vhost*, const char*);
244 int		 vhost_disable_log(struct vhost*, const char*);
245 void		 mark_nonblock(int);
246 void		 loop(struct tls*, int, int);
247 
248 /* ex.c */
249 int		 send_string(int, const char*);
250 int		 recv_string(int, char**);
251 int		 send_iri(int, struct iri*);
252 int		 recv_iri(int, struct iri*);
253 void		 free_recvd_iri(struct iri*);
254 int		 send_vhost(int, struct vhost*);
255 int		 recv_vhost(int, struct vhost**);
256 int		 send_time(int, time_t);
257 int		 recv_time(int, time_t*);
258 int		 send_fd(int, int);
259 int		 recv_fd(int);
260 int		 executor_main(void);
261 
262 /* sandbox.c */
263 void		 sandbox(void);
264 
265 /* utf8.c */
266 int		 valid_multibyte_utf8(struct parser*);
267 char		*utf8_nth(char*, size_t);
268 
269 /* iri.c */
270 int		 parse_iri(char*, struct iri*, const char**);
271 int		 trim_req_iri(char*, const char **);
272 int		 serialize_iri(struct iri*, char*, size_t);
273 char		*pct_decode_str(char *);
274 
275 /* puny.c */
276 int		 puny_decode(const char*, char*, size_t, const char**);
277 
278 /* utils.c */
279 void		 block_signals(void);
280 void		 unblock_signals(void);
281 int		 starts_with(const char*, const char*);
282 int		 ends_with(const char*, const char*);
283 ssize_t		 filesize(int);
284 char		*absolutify_path(const char*);
285 char		*xstrdup(const char*);
286 void		 gen_certificate(const char*, const char*, const char*);
287 X509_STORE	*load_ca(const char*);
288 int		 validate_against_ca(X509_STORE*, const uint8_t*, size_t);
289 
290 #endif